This invention relates to a control system for an accumulating conveyor having zero pressure accumulation. More particularly, the present invention relates to a pneumatic logic system for controlling a zero pressure accumulating conveyor and to a pneumatic logic module particularly adapted for use therewith.
The term "zero pressure" as used in the context of accumulating conveyors refers to an accumulating conveyor having controlled spacing between the containers, pallets or other items being conveyed. Controlled spacings prevents contact between the conveyed items which, in turn, minimizes any damage resulting from the conveying process. Controlled spacing is generally achieved by using a conveyor system having a plurality of independently controlled segments. While accumulating conveyors having zero pressure and employing pneumatic control systems are known in the art, there remains a need for improved control systems which can be economically manufactured and installed and which offer flexibility in operation and design.
Wherefore, it is one object of the present invention to provide an improved pneumatic control system for "zero pressure" accumulating conveyors. Another object of this invention is to provide a practical pneumatic control system which can be economically manufactured, installed and operated. Still another object is to provide an improved pneumatic logic module which is inexpensive to manufacture, install and operate and which serves "AND", "RELAY-LIMIT" and "OR" functions. Yet another object of this invention is to provide a pneumatic control system which is flexible in design, and can be adapted for forward or reverse operation, and single or train release of conveyed articles. A further object of this invention is to provide a pneumatic control system which operates with full factory air pressure to perform both logic control and full power actuating functions and hence is immune to the vulnerability of a low pressure system. Yet another object is to provide a control system which can be adapted for use with power valve actuation means for heavy duty conveyors. These and other objects, features and advantages of the present invention will be apparent from the following disclosure taken in conjunction with the drawings attached hereto.